Gas turbines are widely used in industrial and commercial operations. A typical gas turbine includes an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section. The inlet section cleans and conditions a working fluid (e.g., air) and supplies the working fluid to the compressor section. The compressor section increases the pressure of the working fluid and supplies a compressed working fluid to the combustion section. The combustion section mixes fuel with the compressed working fluid and ignites the mixture to generate combustion gases having a high temperature and pressure. The combustion gases flow to the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a shaft connected to a generator to produce electricity.
The fuel supplied to the combustion section may be a liquid fuel, a gaseous fuel, or a combination of liquid and gaseous fuels. Heating the fuel prior to combustion generally may enhance the efficiency of the combustion and reduce undesirable emissions of nitrous oxides (NOx). In addition, the combustion gases exiting the turbine section generally have considerable residual heat that may be extracted prior to discharge to the environment to further enhance the overall efficiency of the gas turbine. As a result, a system and method for heating the fuel using the combustion gases exiting the turbine section would be useful.